The 1929 crash exposed the naivety and ignorance of bankers, businessmen, Wall Street experts and academic economists high and low; it showed they did not understand the system they had been so confidently manipulating. They had tried to substitute their own well-meaning policies for what Adam Smith called ‘ the invisible hand’ of the market and they had wrought disaster. Far from demonstrating, as Keynes and his school later argued – at the time Keynes failed to predict either the crash or the extent and duration of the Depression – the dangers of a self-regulating economy, the degringolade indicated the opposite: the risks of ill-informed meddling.

– Paul Johnson, Modern Times, p. 240

I teach the chapter entitled Degringolade to my students tomorrow. In context, the chapter title is a trilingual pun. The students’ first assignment was to research the meaning of the title.